SWOLLEN-HEAD-SYNDROME ASSOCIATED WITH ESCHERICHIA-COLI AND INFECTIOUS-BRONCHITIS VIRUS IN THE CENTRAL VALLEY OF CALIFORNIA

A commercial broiler flock in the Central Valley of California experie nced a sudden increase in mortality due to heavy culling. Clinical sig ns included a snick, swollen heads and severe depression. Necropsy and histology revealed tracheitis, rhinitis, facial cellulitis, blepharit is, episcleritis, otitis media and caseous exudate within the air spac es of cranial bones. Escherichia coli serotype O78 was isolated from a ll lesions. Infectious bronchitis virus (Massachusetts serotype) was i solated from trachea/nasal cavity tissue pool. Adenovirus group 1 was isolated from trachea/nasal cavity and caecal tonsil tissue pools. Ser um samples were positive for infectious bronchitis using ELISA and hae magglutination inhibition tests, but negative for turkey rhinotracheit is by an ELISA using the British antigen. This case suggests that swol len head syndrome can be associated with viruses other than pneumoviru s.